1. Field of the Invention
The present invention relates to a system for providing cleaning fluid to the exterior surface of a windshield or other vision unit installed in an automotive vehicle. As used herein, the term xe2x80x9cvision unitxe2x80x9d thus means a glazing panel of a vehicle, whether the panel is fixed or movable.
2. Disclosure Information
Automotive designers have utilized a variable plethora of systems for providing washer fluid or other cleaning liquids to the exterior surfaces of automotive windshields. Typically, automobiles used in areas subjected to sub-freezing temperatures will utilize washer fluid having freezing point depressants. Such depressants are all ultimately released to the atmosphere when the washer fluid is dispensed, and may participate in the formation of photochemical smog. The present inventive system allows the use of washer fluid having either no freezing point depressant chemical or a very low level of such additive, so as to minimize the release of any substance other than neat water to the environment.
U.S. Pat. No. 3,888,412 illustrates a system in which windshield washer fluid is heated by means of a heat exchanger which is itself warmed by circulating engine coolant. A system according to present invention is, however, suitable for use with vehicles either of the electrodrive variety in which no engine is used, or the hybrid style in which both an engine and an electrodrive system including a traction motor are employed.
A windshield washer system for an automotive vehicle includes a reservoir for holding windshield washer fluid, an applicator system for furnishing washer fluid from the reservoir to an exterior surface of a vehicle, and a heat transfer system for recovering heat from a braking system of the vehicle and for conveying the recovered heat to the washer fluid contained within the reservoir.
According to another aspect of the present invention, a braking system may comprise either a friction braking system including one or more brake calipers or expanding internal brakes, or it may comprise a regenerative braking system of an electrodrive vehicle having at least one traction motor, with the heat transfer system circulating a fluid through the traction motor to recover heat from the traction motor and to transfer the recovered heat to the windshield washer fluid reservoir.
According to another aspect of the present invention, the present system may further comprise a heat exchanger for transferring heat from engine coolant to washer fluid within the washer fluid reservoir.
According to another aspect of the present invention, a windshield washer system according to this invention may be employed in connection with a heated windshield.
According to another aspect of the present invention, a method for providing heated washer fluid to the windshield of an automotive vehicle may comprise the steps of maintaining a supply of washer fluid within the reservoir, recovering heat from a braking system of the vehicle, conveying the recovered heat to the washer fluid within the reservoir, and furnishing heated fluid from the reservoir to the windshield.
It is an advantage of the present invention that heat which would otherwise be rejected to the environment is used to reduce the need for anti-icing agents which could participate in the formation of photochemical smog.
It is a further advantage of the present invention that the windshield washer fluid may be heated so as to assist in de-icing the windshield when the engine of a hybrid vehicle is operating at an average power level that is insufficient to generate enough waste heat to warm the washer fluid and windshield.
Other advantages, as well as objects and features of the present invention, will become apparent to the reader of this specification.